The proposed studies target the well-vascularized and refractory class of central nervous system [CNS] tumors for the development of novel methods for detecting the presence and quantitating amounts of specific tumor-produced angiogenesis factors [AF]. Cell homogenates and conditioned media from cell cultures of animal and human CNS tumors will be employed in these Phase I studies. Two kinds of AF molecules will be sought by the screening studies: 1) low molecular weight factor (less than 1000 daltons) and 2) higher mol.wt. polypeptides (greater than 16,000d). Fractionation of the tumor cell-derived samples will be accomplished using ultrafiltration or extraction methods and, if necessary, chromatographic methods. The activities of these materials will be determined using an angiogenesis (CAM) assay as well as two in vitro assays that correspond to separate steps of the angiogenic process (vascular endothelial cell [EC] proliferation and migration). Immunoassays that are based on the reported procedures for a low mol.wt. AF and polypeptide AF will be developed for detecting active molecules in these CNS tumor preparations. The protocols from these studies will be used in Phase II to measure AF content in tissue and cerebrospinal fluid [CSF] samples from CNS cancer patients.